While Monday's snowy weather over the Zagros region and Iran's Central Plateau has intensified the winter cold for residents of many Iranian cities, people in the United States have also been dealing with exceptional cold over the past few days.
Temperatures have dropped sharply across the northern and central United States. Cities along the Gulf of Mexico coast, whose climate is reminiscent of coastal cities in southern Iran, experienced temperatures below freezing last night, while farther north temperatures fell as low as −20°C. Cold approaching −25°C in Chicago led to the cancellation of all flights. Forecasts also indicated that freezing conditions would persist across the central and eastern United States for another two to three days.
The article attributes these conditions to a weakening of the fast atmospheric currents circulating around the polar regions. Under normal conditions, these currents prevent frozen polar air from penetrating farther south. Similar conditions have also contributed to falling temperatures elsewhere.
Accordingly, temperatures in Iran were expected to decline noticeably over the following few days, with the largest drops in the northwest, along the Zagros slopes, and across the central desert regions, where temperatures could fall to −10°C. These conditions were expected to continue into the following week.
With another system entering Iran from the west and southwest the following Saturday, renewed snowfall was considered likely in western Iran, the Zagros region, and central areas. The author notes that further analysis of the system would be posted by Saturday.